Social media has become unsocial, chockful of fake news, extremism and sexism, and one of the world's biggest advertisers has had enough of it.

Unilever is threatening to pull its advertising from digital platforms that it says have become a "swamp." Keith Weed, head of marketing at Unilever is expected to deliver a forceful warning to digital platforms such as Google during an advertising conference in California later today.

"We cannot continue to prop up a digital supply chain ... which at times is little better than a swamp in terms of its transparency," Weed will tell attendees at the annual Interactive Advertising Bureau conference in Palm Desert, CA, on Monday, according to a copy of his speech obtained by CNN.

As the No. 2 advertiser in the world, Unilever spends about 25% of its $10 billion marketing budge on digital platforms.

"This is not something that can brushed aside or ignored," he will say in the speech.

Unilever would no longer advertise on platforms that create divisions in society or fail to protect young people.

Facebook and Google have dominated the online ad market for years, thanks to their massive reach and vast amounts of data. Together, they received more than 60% of digital ad spending in 2017—a statistic that has advertisers alarmed. Facebook said in a statement that it supports Unilever's commitments and is "working closely with them." Google did not respond to a request for comment.

"2018 is either the year of techlash, where the world turns on the tech giants—and we have seen some of this already—or the year of trust," Weed will say. "The year where we collectively rebuild trust back in our systems and our society."

Weed's words are worth heeding. He was just named the first Global Marketer of the Year by the World Federation of Advertisers and Campaign magazine. The new award recognizes “marketers who drive more effective and sustainable marketing.”